The relationship between chronotype and mood fluctuation in the general population

Area of Science:

• Psychiatry
• Sleep Medicine
• Chronobiology

Background:

• Limited research exists on the connection between chronotype and subthreshold mood fluctuations.
• Understanding this relationship is crucial for identifying individuals at risk for mood disorders.

Purpose of the Study:

• To investigate the association between chronotypes (morningness, intermediate, eveningness) and mood fluctuation in a general population sample.
• To explore if eveningness is linked to higher levels of subthreshold mood instability.

Main Methods:

• 302 participants without a history of major mood episodes were assessed.
• Chronotype was determined using the Korean Composite Scale of Morningness (CSM).
• Mood fluctuation was measured using the Mood Disorder Questionnaire (MDQ) and Bipolar Spectrum Diagnostic Scale (BSDS).

Main Results:

• No significant differences were found in MDQ scores across the three chronotype groups.
• Significant differences emerged in total BSDS scores.
• The eveningness group exhibited higher BSDS-D and BSDS-M scores compared to morningness and intermediate groups, even after adjusting for age.

Conclusions:

• Eveningness chronotype is associated with increased mood fluctuation, specifically related to soft bipolarity symptoms.
• Chronotype, particularly eveningness, may be an important factor in subthreshold mood instability.
• Further research is warranted to explore the clinical implications of eveningness in mood regulation.